The iPhone XS & XS Max Review: Unveiling the Silicon Secrets
by Andrei Frumusanu on October 5, 2018 8:00 AM EST- Posted in
- Mobile
- Apple
- Smartphones
- iPhone XS
- iPhone XS Max
Battery Life
The iPhone XS comes with a 2658mAh/10.13Wh battery, while the XS Max has a capacity of 3174mAh/12.08Wh. Again, it’s to be noted that although both phones are quite large form-factor devices by now, Apple’s battery density still largely lags behind the competition. While yes, it’s true that the XS Max’ battery is the biggest that Apple has ever used, it still pales in comparison to the 3500 to 4000mAh that other vendors now employ in the same form-factor.
As we saw in the SPEC analysis, the one advantage that Apple has is an enormous lead in terms of power efficiency of its SoC, which largely makes up for any gap in the battery capacity deficit.
Our web browsing test is a mixed-to-heavy workload that iterates through a set of popular webpages that are hosted on our server. The test loads a web page, pauses, scrolls through it, pauses, and then continues to the next in the set, repeating all over when done. Brightness is fixed at 200cd/m².
The iPhone XS saw a very slight degradation compared to the iPhone X in our test. The 19 minute deficit isn’t terrible, but it does come at a surprise given that Apple had promised improved battery life for the new model. What’s happening is that likely our test is a tad heavier in its workload than what Apple and many other vendors internally test to advertise as the daily battery life of their devices.
The iPhone XS Max came in at 10.3h. Again while this is still good, it’s a degradation over the 11.83h of the iPhone 8 Plus. Here it’s easier to rationalise the difference; the OLED screen of the XS Max is just more power hungry and also has a larger area than the iPhone 8 Plus. Here the increased battery capacity isn’t enough to counteract the panel’s increased needs.
As to why the iPhone XS saw a degradation over the X, I’m not too sure. I did rerun the test on the iPhone X to make sure iOS12 hadn’t impacted the devices – and I got a runtime just 10 minutes lower than what I had tested on the iPhone X back around in January, so the iOS upgrade certainly doesn’t seem to have affected the battery life.
It should be relatively safe to assume that the new A12 should be more efficient in its workloads, even with the increased performance that it brings. One thing that we can’t really verify is the power efficiency at intermediate performance states, as that’s also where CPUs perform a lot of their work at.
We also have to keep in mind the connectivity factor: the new iPhone’s seems to sport a new Broadcom BCM4377 WiFi combo chip which we don’t know much about. Most importantly the new XS have also switched over from a Qualcomm baseband (in our test unit of the iPhone X) to a new Intel XMM7560 baseband.
I’ve generally given up on LTE testing after a few years ago I had run into some serious issues regarding a misconfiguration of my mobile carriers’ baseband stations as they did not have CDRX enabled. This caused an almost 20-30% battery life degradation on Huawei’s devices – and if I hadn’t debugged the issue with HiSilicon I’d probably be none the wiser. Fact is, cellular battery life testing is a lot harder than one would think, and without having a controlled environment, I’m very hesitant to resume cellular battery life testing.
That being said, I will revisit the iPhone X vs iPhone XS battery life topic while on LTE over the weekend and post an update to the review.
Overall, the battery life of the iPhone XS and XS Max are good – they don’t quite reach Apple’s claimed improvements, but that also just might be something that will vary from use-case to use-case.
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willis936 - Friday, October 5, 2018 - link
Great review. I loved the SoC analysis. There's definitely something spooky going on in an SoC with three caches that are scattered throughout the die. You do mention that there are two more fixed point ALUs but when analyzing a SPEC test result that relies on execution units you said that the A12 didn't have any execution improvements. Aren't the extra ALUs more execute?It's clearly a nice device and there are areas that saw massive improvements and other areas that are more of the same. I really appreciate that your conclusion isn't "it's a great device so buy it" but "it's a great device but really expensive".
Andrei Frumusanu - Friday, October 5, 2018 - link
The A11 had two more ALUs over the A10, the A12 doesn't improve in this regard.3DoubleD - Friday, October 5, 2018 - link
More than half the die shot was unlabeled. I found it strange that over 50% of the die wasn't worth discussing... what does it do? Are these fixed function units, modems, ISPs, ect.?It's really amazing how the CPU and GPU are taking less and less space on a SoC.
shabby - Friday, October 5, 2018 - link
It's not like Apple gives out these die shots with everything labeled, we're basically guessing what everything is.melgross - Saturday, October 6, 2018 - link
Nobody knows what the entire chip does. Since Apple doesn’t sell their chips they’re not obligated to tell us all of the secret sauce that’s in there.Ironchef3500 - Friday, October 5, 2018 - link
Thanks for the review!bull2760 - Friday, October 5, 2018 - link
I returned my MAX because of antenna signal issues. I upgraded from the 8 plus and while it was super fast it definitely has issues. I drive the same route to work everyday and in the few days I had the phone I had 4 dropped calls in the middle of conversations and when I looked at the screen is said call failed. One call to my wife I had 2 calls failed within 5 minutes. From my research the dropped calls are related to the new antenna system that Apple is using. Unless you are in a strong signal area you will receive a lot of dropped calls. From what I'm reading this has nothing to do with switching to Intel from 3Com it is directly related to the choice of antennas. Had 3Com had a chip ready to go with the same specs it too who have similar signal issues because of the antennas. The other issue I was having was network connectivity. I would be connected to my wireless at home or at work and often get page cannot be displayed errors and I need to check my network. I was clearly connected to my wireless network. I would turn the wireless on and off and it would start working. Speeds were crazy too. One minute you'd get really fat throughput and the next it would be crazy slow. I'd hold off on purchasing the new phones until Apple sorts out the bugs.FunBunny2 - Friday, October 5, 2018 - link
ehh?? everybody knows that if you want to use a telephone, you get a landline. mobile phones ceased being about phone calls at least a decade ago. what?? for a Grand$ you want to talk to someone??? how Neanderthal.PeachNCream - Friday, October 5, 2018 - link
Hah! I love the sarcasm!On a serious note though, I do wonder how long we'll even have a phone network or carriers that treat voice, text, and data as individual entities. We can and have already been able to do VoIP for what feels like ever and calling over WiFi is a thing. It'd make sense to just buy data and wrap up voice and text inside 4G or whatever.
FunBunny2 - Friday, October 5, 2018 - link
"It'd make sense to just buy data and wrap up voice and text inside 4G or whatever."I suspect that some scientists/engineers have run the numbers to see what that does to data capacity. which may be why it hasn't happened. or, it could also be that the data scientists at the carriers (and phone vendors) have found that smartphone users really don't make enough phone calls to warrant supporting decent quality.